Ssh_fx_failure with mergerfs

Hi there,
I am receiving an error "Failed to upload the chunk … : sftp: “Failure” (SSH_FX_FAILURE) when using SFTP storage.

I did see another forum post that mentioned this error, but the cause seemed to have been related to using a raspberry on the storage side.

A few notes:

  • My storage side is local, a fairly well powered Intel NUC, with external drives over USB3 merged using mergerfs.
  • This has been successfully working for some time now, and only just began receiving this error over the past month or so.
  • I am able to move past the error by mapping to a non mergerfs drive
  • Using duplicacy_web on a different device, mapping to the same SFTP storage point (backed by mergerfs), has no issue.

Mergerfs is the likely culprit, but I would like to ask if anyone has seen a similar issue, or has suggestions on how to troubleshoot further.